Invasive medical devices including magnetic region and systems and methods

Abstract

Devices, systems, and methods are described including an invasive medical device with a magnetic region. The magnetic region can include a discontinuity in the magnetic region providing a diameter transition, a plurality of spaced magnetic regions can be provided or the magnetic regions can be encoded with data. Systems and methods are described that include ways to read the data.

What is claimed is: 
     
       1. An invasive medical device for insertion into a patient, the invasive medical device comprising:
 a hypodermic needle comprising a stainless steel elongate shaft having a diameter, an outer surface, a distal tip, and a proximal end, the diameter of the elongate shaft sized to be inserted within an intravenous catheter, at least a portion of the elongate shaft having a first magnetic region comprising a first magnetic field B 1  having a known magnetic field strength, a vector, and a first length L 1 , and placed at a known location at first fixed distance from the distal tip and spaced apart at a distance d 1  from a second magnetic region comprising a second magnetic field B 2  having a known magnetic field strength, a vector, and a second length L 2  and placed at a known location at second fixed distance from the distal tip, and a third magnetic region spaced from the second magnetic region at a distance d 2  and comprising a third magnetic field B 3  having a known magnetic field strength, a vector, and a third length L 3 , wherein L 1  and L 2  are not equal, wherein L 2  and L 3  are not equal, and wherein L 1 , L 2  and L 3 , and d 1  and d 2  are utilized to encode the hypodermic needle with information on the elongate shaft, wherein the first magnetic region and the second magnetic region are separated by a non-magnetized region and wherein the second magnetic region and the third magnetic region are separated by a non-magnetized region, wherein the first magnetic region, the second magnetic region and the third magnetic region alternate in pole orientation to encode the hypodermic needle with information on the elongate shaft, wherein the information includes one or more of diameter, length and type of device. 
 
     
     
       2. The invasive medical device of  claim 1 , wherein at least one of the first magnetic region and the second magnetic region is selected from the group consisting of a layer of ferromagnetic metal, a layer of paramagnetic metal, a notch in the outer surface of the elongate shaft, a spot weld of magnetic metal, a ferrule and combinations thereof. 
     
     
       3. A system comprising the invasive medical device of  claim 1  and further comprising an ultrasound system comprising a three-dimensional grid array of magnetometers, wherein the ultrasound system is configured to determine a position of the first magnetic region, the second magnetic region and the third magnetic region of the hypodermic needle. 
     
     
       4. The invasive medical device of  claim 1 , wherein at least one of the first magnetic region, the second magnetic region and the third magnetic region comprises martensitic steel. 
     
     
       5. An invasive medical device for insertion into a patient, the invasive medical device comprising:
 a hypodermic needle comprising a stainless steel elongate shaft having a diameter, an outer surface, a distal tip, and a proximal end, the diameter of the elongate shaft sized to be inserted within an intravenous catheter, at least a portion of the elongate shaft having a first magnetic region comprising a first magnetic field B 1  having a known magnetic field strength, a vector, and a first length L 1 , and placed at a known location at first fixed distance from the distal tip and spaced apart at a distance d 1  from a second magnetic region comprising a second magnetic field B 2  having a known magnetic field strength, a vector, and a second length L 2 , and placed at a known location at second fixed distance from the distal tip, and a third magnetic region spaced from the second magnetic region at a distance d 2  and comprising a third magnetic field B 3  having a known magnetic field strength, a vector, and a third length L 3 , wherein the first magnetic region is adjacent the distal tip and B 1  and B 2  are not equal and L 1  and L 2  are not equal, wherein L 2  and L 3  are not equal, and wherein L 1 , L 2  and L 3 , and d 1  and d 2  are utilized to encode the hypodermic needle with information on the elongate shaft, wherein the first magnetic region and the second magnetic region are separated by a non-magnetized region and wherein the second magnetic region and the third magnetic region are separated by a non-magnetized region, wherein the first magnetic region, the second magnetic region and the third magnetic region alternate in pole orientation to encode the hypodermic needle with information on the elongate shaft, wherein the information includes one or more of diameter, length and type of device. 
 
     
     
       6. The invasive medical device of  claim 5 , wherein the second magnetic region is spaced proximally from the first magnetic region. 
     
     
       7. The invasive medical device of  claim 6 , wherein each of the first magnetic region, the second magnetic region and the third magnetic region comprise at least one of a layer of ferromagnetic metal, a layer of paramagnetic metal, a spot weld of magnetic metal, a ferrule and combinations thereof. 
     
     
       8. The invasive medical device of  claim 5 , wherein each of the first magnetic region and the second magnetic region comprise at least one of a layer of ferromagnetic metal, a layer of paramagnetic metal, a spot weld of magnetic metal, a ferrule and combinations thereof. 
     
     
       9. A system comprising the invasive medical device of  claim 7  and an ultrasound system including a three-dimensional grid array of magnetometers, wherein the ultrasound system for determining relative position of the hypodermic needle is configured to determine an x, y, or z position of the first magnetic region and the second magnetic region. 
     
     
       10. The system of  claim 9 , wherein the hypodermic needle is part of a needle subassembly further including a needle hub mounted to the proximal end of the hypodermic needle, and the intravenous catheter is part of a catheter adapter subassembly, the catheter adapter subassembly including a magnetic feature. 
     
     
       11. The system of  claim 10 , wherein the ultrasound system is configured to detect the known magnetic field strength, vector, length and spacing of the first magnetic region from the second magnetic region and the third magnetic region. 
     
     
       12. The system of  claim 11 , wherein the ultrasound system calculates the position of the hypodermic needle. 
     
     
       13. The system of  claim 11 , wherein the ultrasound system is configured to determine relative motion of the hypodermic needle and the catheter adapter subassembly.